Dual-clutch transmission arrangement, and motor vehicle

ABSTRACT

A dual clutch arrangement for a dual clutch transmission includes a first clutch and a second clutch. The output of the first clutch is connected to the input of the second clutch. A dual clutch transmission arrangement with the dual clutch arrangement and a motor vehicle with the dual clutch arrangement are also provided.

FIELD OF THE INVENTION

The invention relates generally to a dual clutch arrangement for a dual clutch transmission that includes a first clutch and a second clutch.

BACKGROUND

Dual clutch transmissions are known, in which two clutches for connecting the internal combustion engine to a transmission input shaft in each case are arranged between the engine and the transmission as a dual clutch module or a dual clutch arrangement.

In order to hybridize dual clutch transmissions, it is additionally known to allow an electric motor to act on the transmission or on one or both transmission input shafts. A separating clutch is additionally required in order to entirely decouple the internal combustion engine from the drive train. Superstructures are known, in which the clutches and the separating clutches are nested with one another as a triple clutch arrangement.

SUMMARY OF THE INVENTION

On the basis thereof, example aspects of the present invention provide a dual clutch arrangement, with the aid of which a hybridization of the drive train is possible and in the case of which the design and manufacturing costs are nevertheless low.

In order to solve this problem, a dual clutch arrangement for a dual clutch transmission that includes a first clutch and a second clutch with the output of the first clutch connected to the input of the second clutch. In other words, this means the first clutch is the separating clutch, which is preferably utilized in the case of the hybridization, and the second clutch is utilized for establishing a connection between the internal combustion engine or, more generally, the first drive unit, and the transmission. These two clutches form a module, while the third clutch, which is still required, for connecting the engine to the second sub-transmission is located somewhere else in the transmission housing.

In this case, the dual clutch arrangement is advantageously designed as a preassembled module. This means, the first clutch and the second clutch are preinstalled in a housing and are mounted, for example, by being slipped over the transmission input shafts. Therefore, this dual clutch arrangement is not a triple clutch arrangement even for the case in which the second sub-transmission clutch would be installed directly next to the dual clutch arrangement. In particular, the cost advantages in the design and assembly result from the fact that a known dual clutch module is to be modified as little as possible, namely in that the output of the first clutch is placed onto the input of the second clutch instead of at one of the transmission input shafts; for the rest, the superstructures can be completely incorporated. Therefore, no recalculations are necessary with respect to the space required, the manufacturing process, or the like. These advantages do not result only when the dual clutch arrangement is designed as a preassembled module, of course. In practical applications, however, dual clutch arrangements are utilized exclusively as preassembled modules.

In the present invention, a clutch is understood to be a clutch, which can transmit the torque output by a prime mover as a drive unit, in particular, an internal combustion engine and an electric motor. This is intended merely for further delimitation from synchronizing mechanisms, which are also referred to, in part, as separating clutches. Such synchronizing mechanisms can only take up much less torque than that output by the prime mover.

Preferably, the clutches are designed as a friction clutch.

As described above, the first clutch is advantageously a separating clutch for disconnecting an internal combustion engine from the rest of the drive train. These types of separating clutches are utilized in the case of hybridized transmissions, as described above, in order to disconnect the internal combustion engine from the drive train.

As described above, the second clutch can be designed for connection to a transmission input shaft. The second clutch is therefore a main clutch or, more precisely, a powershift clutch. Preferably, the second clutch can also be designed as a launch clutch.

In this embodiment, the dual clutch arrangement has only a separating clutch and a launch clutch, wherein the output of the separating clutch is connected to the input of the launch clutch.

Preferably, the second clutch can be designed for connection to two shafts. Depending on the definition, these are two transmission input shafts or one transmission input shaft and a connecting shaft to the second powershift clutch.

In addition, the second clutch can be designed for connection to a transmission input shaft and to the second powershift clutch or to a third clutch. In particular, the output of the second clutch can be designed for connection to a transmission input shaft and to the third clutch. It is irrelevant whether the third clutch is located in the spatial proximity of the dual clutch arrangement, or not. As described above, the output of the second clutch can also be connected to the third clutch, for example, via a connecting shaft or a transmission input shaft.

Advantageously, the first clutch and the second clutch can be arranged in a radially nested manner. In this case, advantageously, the first clutch can be arranged radially outward and the second clutch can be arranged radially inward. The first clutch and the second clutch overlap at least partially in the axial direction.

Preferably, the input of the first clutch can be connectable to a first drive unit. Damper units, such as a dual-mass flywheel or a damper or the like, can be located between the first drive unit, which is usually designed as an internal combustion engine, and the first clutch. The statement that the first clutch is connectable to the first drive unit means that the first clutch is designed at the input in such a way that the first clutch can be connected to the first drive unit. This can involve a flange or a spline or the like.

Moreover, the dual clutch arrangement can be connectable to a second drive unit. In particular, the input of the second clutch can be connectable to a second drive unit. This means, simultaneously, that the output of the first clutch is connectable to the second drive unit, since the output of the first clutch and the input of the second clutch are connected.

Preferably, the clutches can be designed as multi-disk clutches. Moreover, the clutches can be designed to be wet-running. In an embodiment as multi-disk clutches, the input and the output can be designed as disk carriers.

Advantageously, an output disk carrier of the first clutch and an input disk carrier of the second clutch can include a common section. This can be an inner disk carrier or an outer disk carrier, respectively, as described further below.

The invention also relates generally to a dual clutch transmission arrangement. This is distinguished by the fact that the dual clutch transmission arrangement includes a dual clutch arrangement as described above.

Advantageously, the dual clutch transmission arrangement can include a third clutch, which connects the internal combustion engine to a transmission input shaft and is arranged within the gear set housing. The third clutch is also a powershift clutch, as is the second clutch, although the third clutch does not need to be designed as a launch clutch. The second and the third clutches, just as the first clutch, are designed, in particular, for transmitting the total torque made available by the first drive unit.

Advantageously, the third clutch can be arranged between two gear set planes. A gear set plane is usually considered to be the axial area occupied by the gearwheels of one or two gears. There is an axial distance between the gear set planes, in which, for example, shift elements can be arranged.

The third clutch can be arranged between the gear sets of odd gears. Alternatively, the third clutch can be arranged between the gear sets of even gears. Further alternatively, the third clutch can be arranged between the gear sets of even gears and odd gears. Each of the embodiments has its own advantages and disadvantages. An arrangement between even and odd gear sets is preferred. Regardless of the precise arrangement of the gear sets, the third clutch can be arranged at the end of the hollow transmission input shaft. Usually, this is also the point at which the third clutch is located between the even gear set planes and the odd gear set planes.

The reverse gear is considered, in principle, to be an even gear in this case; this applies at least for as long as a gearwheel of the reverse gear is located on the transmission input shaft that has the even gears. This assignment is not always unambiguously implementable, however, since both transmission input shafts or two countershafts are utilized, in part, for forming the reverse gear. In a further alternative, the third clutch can be located between the gear set plane of the reverse gear and another gear set plane; this gear set plane can have even gears or odd gears.

Alternatively to the arrangement between two gear set planes, the third clutch can be arranged, on the transmission-end side, downstream from the gear set planes. In other words, the third clutch can be arranged on the end of the gear set housing facing away from the engine.

Advantageously, the third clutch can enclose a shaft. In the case of the arrangement between the gear set planes, the third clutch can be arranged between multiple shafts. The cavity usually present in the center of a third clutch can also be utilized, however, for sliding the third clutch onto a shaft. This encompasses the embodiment in which the third clutch has been slid onto the hollow transmission input shaft and then encloses two shafts.

In a further embodiment, the third clutch can enclose multiple shafts, specifically parallel, non-coaxial shafts. In the extreme case, the third clutch can be located on the inside of the transmission housing, although, due to the resultant diameter, a uniform actuation around the perimeter is made difficult as a result. It is therefore preferred when the third clutch encloses only one shaft.

Preferably, the dual clutch transmission arrangement has a countershaft design. This is intended merely for purposes of clarification.

The invention also relates generally to a motor vehicle that includes a dual clutch transmission arrangement and/or a dual clutch arrangement. The motor vehicle is distinguished by the fact that the dual clutch arrangement and/or the dual clutch transmission arrangement are/is designed as described above.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages, features, and details of the invention result from the following description of exemplary embodiments and figures. Wherein:

FIG. 1 shows a motor vehicle,

FIG. 2 shows a diagrammatic configuration of a dual clutch transmission arrangement in a first embodiment,

FIG. 3 shows a diagrammatic configuration of a dual clutch transmission arrangement in a second embodiment,

FIG. 4 shows a dual clutch arrangement in a first embodiment,

FIG. 5 shows a dual clutch arrangement in a second embodiment,

FIG. 6 shows a dual clutch arrangement in a third embodiment,

FIG. 7 shows a dual clutch arrangement in a fourth embodiment,

FIG. 8 shows a dual clutch arrangement in a fifth embodiment,

FIG. 9 shows a portion of a dual clutch transmission arrangement in a first view,

FIG. 10 shows a portion of a dual clutch transmission arrangement in a second embodiment, and

FIG. 11 shows a dual clutch transmission arrangement in a third view.

DETAILED DESCRIPTION

Reference will now be made to embodiments of the invention, one or more examples of which are shown in the drawings. Each embodiment is provided by way of explanation of the invention, and not as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be combined with another embodiment to yield still another embodiment. It is intended that the present invention include these and other modifications and variations to the embodiments described herein.

FIG. 1 shows a motor vehicle 1 including a first drive unit 2, a second drive unit 3, a dual clutch transmission arrangement 4, and a differential 5. A transmission housing usually consists of two parts, namely the clutch bell housing 7 and the gear set housing 8, which accommodates the gear set. The clutch bell housing 7 and the gear set housing 8 are usually fixedly flanged to one another; an intermediate wall 9 can be located therebetween. The intermediate wall 9 is designed to be oil-tight, depending on whether the oil spaces of the clutch bell housing and of the gear set housing are to be separated. At the least, the intermediate wall 9 is usually utilized for mounting at least a portion of the shafts of the dual clutch transmission arrangement 4.

The second drive unit 3, in particular an electric motor, can act on the drive train either as indicated with the aid of the line 10 or as indicated with the aid of the line 12. A cooperation with one or both transmission input shafts is referred to as a P2 configuration and a cooperation with the transmission itself is referred to as a P3 configuration.

The clutches for connecting the first drive unit 2 to one of the transmission input shafts of the dual clutch transmission arrangement 4 in each case are referred to as clutches in the following. The clutch for disconnecting the internal combustion engine from the dual clutch transmission arrangement 4 is referred to as a separating clutch K0.

FIG. 2 shows a first embodiment of a dual clutch transmission arrangement 4 and, in fact, as a gear set scheme. The separating clutch K0 is coupled to the first drive unit 2. Damping devices, such as a dual-mass flywheel or a rotational speed-adaptive damper, can be arranged between the first drive unit 2 and the separating clutch K0. In these embodiments as well, the separating clutch K0 disconnects the first drive unit 2 from the rest of the drive train. In particular, the connection between the first drive unit 2 and the separating clutch K0 can be considered to be a direct connection even when a dual-mass flywheel or a rotational speed-adaptive damper is present, since the above-mentioned components are to merely reduce vibrations, but not to release the connection between the drive unit 2 and the separating clutch K0.

The drive unit 2 is therefore located at the input 14 of the separating clutch K0. The output 16 of the separating clutch K0, however, is connected to the input 18 of the first clutch K1. The output of the first clutch K1 is coupled to the first transmission input shaft 22. The coupling usually takes place with the aid of a spline. FIG. 2 shows an embodiment of the transmission input shaft 22 as a hollow shaft. As a result, the separating clutch K0 can be connected via the connecting shaft 24 to the input 26 of the second clutch K2. The output 28 of the second clutch K2 is then connected to the second transmission input shaft 30, which is also designed as a hollow shaft and which encloses the connecting shaft 24. The various gear steps can be implemented with the aid of the first/fixed gears 32, the second/idler gears 34, and the shift elements 36. Gear set planes 38 and gear set planes 40 are formed, wherein the gear set planes 38 are the gear set planes associated with the first transmission input shaft 22 and the gear set planes 40 are the gear set planes associated with the second transmission input shaft 30. The representation of the gear set planes 38 and 40 is diagrammatic insofar as they are to merely indicate the presence of gear set planes 38, for example, for even gears, and gear set planes 40, for example, for odd gears. However, a limitation to a certain number of, for example, fixed gears on the first transmission input shaft 22 or on the second transmission input shaft 30 is not to be applied. The gear set 42 also encompasses one or two countershafts 44, which cooperate with fixed gears 46, which lead to the driven end or to the differential. The connection of the second drive unit 3 can take place with the aid of a gearwheel 48, which is arranged between the separating clutch K0 and the first clutch K1 in FIG. 2. In this way, the second drive unit 3 is connectable to both transmission input shafts; the arrangement corresponds to a P2 configuration.

The configuration of the gear set 42 is arbitrary, in principle; the dual clutch transmission arrangement 4 differs from the prior art in that the clutch K2 is arranged in the gear set housing 8, while the clutch K1 is arranged in the clutch bell housing 7. In the embodiment according to FIG. 2, the clutch K2 is arranged, on the transmission-end side, downstream from the gear set planes 38 and 40. It is therefore located at the end of the transmission housing 6 facing away from the engine.

FIG. 3 shows a similar embodiment as in FIG. 2. The comments made with respect to FIG. 2 therefore also apply for FIG. 3. The differences are explained in the following.

In contrast to FIG. 2, the clutch K2 is arranged between various gear set planes and, in fact, between gear set planes 38 and 40, i.e., therefore, between the gear set planes of even gears and odd gears. Due to this arrangement, the second transmission input shaft 30 is also not designed as a hollow shaft and it does not enclose the connecting shaft 24. For the rest, the gear set 42 according to FIG. 3 corresponds to the gear set 42 according to FIG. 2.

FIG. 4 diagrammatically shows a dual clutch arrangement including the separating clutch K0 and the clutch K1. In this embodiment, the separating clutch K0 and the clutch K1 are arranged in a radially nested manner, wherein the separating clutch K0 is located radially outward. The input 14 of the separating clutch K0 is formed by the inner disk carrier 50 of the separating clutch K0. The separating clutch K0 is designed as a multi-disk clutch and therefore includes, in addition to the inner disk carrier 50, an outer disk carrier 52 and a disk pack consisting of nested outer clutch disks and inner clutch disks. The second drive unit 3 is connected to the outer disk carrier 52 and, therefore, to the output 16 of the separating clutch K0. The input 18 of the clutch K1 is also connected to the output 16 in the form of the outer disk carrier 52. The input 18 of the clutch K1 is formed by the outer disk carrier 54. The output 20 of the clutch K1 is implemented with the aid of the inner disk carrier 56, the inner disk carrier 56 connects the clutch K1 to the transmission input shaft 22, designed as a hollow shaft. In the case of the clutch K1 as well, which can also be designed as a multi-disk clutch, inner clutch disks and outer clutch disks, which form a disk pack, are located between the input and the output or between the outer disk carrier 54 and the inner disk carrier 56.

Moreover, the input 18 of the clutch K1, i.e., the outer disk carrier 54, is connected to the connecting shaft 24. In this way, the second drive unit 3 can also be connected to the input of the clutch K2 via the input of the clutch K1.

In all exemplary embodiments, the transmission input shaft 30 is understandable either as a multiple-part shaft or the connecting shaft 24 can also be considered to be a transmission input shaft. In this case, the shaft referred to in FIGS. 2 and 3 as the transmission input shaft 30 can also be considered to be the first output shaft. Therefore, a strict definition of function is not to be associated with these concepts; they are utilized primarily for differentiating the individual components of the dual clutch transmission arrangement 4.

It is known, in principle, to connect the two input sides of the clutches of a dual clutch transmission to one another. Usually, however, the disk carriers are directly connected to one another and not via a connecting shaft 24. The connection of the input sides 18 and 26 of the clutches K1 and K2, respectively, with the aid of a shaft allows for the spatially separated arrangement of the clutches K1 and K2. Such an arrangement is not specifically known from the prior art.

FIGS. 5 through 8 show further embodiments of dual clutch arrangements 48. In these cases, the clutch K1 is located radially outward and the separating clutch K0 is located radially inward. Depending on the embodiment of the disk carriers, the second drive unit 3 can be located either on the transmission side or on the engine side, i.e., on the side of the first drive unit 2.

In the embodiment according to FIG. 5, the inner disk carrier 50 forms the input 14 of the separating clutch K0 and the outer disk carrier 52 forms the output 16. The output 16 or the outer disk carrier 52 is connected to the input 18 of the clutch K1, specifically the outer disk carrier 54 and the connecting shaft 24 in this case. Therefore, the output 16 of the separating clutch K0 is connected to the input of the clutch K1 as well as to the input of the clutch K2. The output of the clutch K1 is formed by the inner disk carrier 56, which connects the clutch K1 to the transmission input shaft 22. The connection usually takes place with the aid of a spline, as described above in several cases. In this embodiment, the second drive unit 3 on the gear set side is connected to the dual clutch arrangement 48. The connection takes place via the input of the clutch K1 and, therefore, automatically via the output of the separating clutch K0.

FIG. 6 shows a configuration similar to that of FIG. 5, which even coincides with the configuration according to FIG. 5 with respect to the separating clutch K0. In the case of the clutch K1, however, the inner disk carrier 56 is utilized as the input 18 and the outer disk carrier 54 is utilized as the output 20. Therefore, the second drive unit 3 can also be arranged on the engine side, i.e., on the side of the drive unit 2. The output 20 of the clutch K1 is coupled, in turn, to the transmission input shaft 22.

FIG. 7 shows a modification of the embodiment according to FIG. 5, in which the input of the separating clutch K0 is formed by the outer disk carrier 52 and the output 16 of the separating clutch K0 is formed by the inner disk carrier 50. Since the embodiment is identical with respect to the clutch K1, the second drive unit 3 is connected, in turn, on the transmission side. In this embodiment as well, the output 16, i.e., the inner disk carrier 50, of the separating clutch K0 is connected to the input 18, specifically the outer disk carrier 54 in this case, of the clutch K1, and to the input 26 via the connecting shaft 24.

FIG. 8 shows an embodiment in which the function of inner disk carriers and of outer disk carriers as input and output has been interchanged as compared to FIG. 5. Therefore, the outer disk carrier 52 forms the input of the separating clutch K0 and the inner disk carrier 50 forms the output 16. The input 18 of the clutch K1 is therefore formed by the inner disk carrier 56 and the output 20 is formed by the outer disk carrier 54. Therefore, the outer disk carrier 54 is connected to the transmission input shaft 22.

A feature common to all embodiments of FIGS. 4 through 8 is that the output 16 of the separating clutch K0, whether it be the inner disk carrier 50 or the outer disk carrier 52, is connected to the inputs 18 of the clutch K1 and to the input 26 of the clutch K2.

FIG. 9 shows a possible implementation of the diagrammatic representation according to FIG. 4, in which the separating clutch K0 is located radially outward and the clutch K1 is located radially inward. Details of the dual clutch transmission arrangement are represented, which are known, in principle, apart from the arrangement of the clutches K0 and K1 with respect to one another. For example, the drive train can include a dual-mass flywheel 58. For example, the clutches can also include pressure compensating cavities 60, in which recoil springs 62 are present. A pressure compensating cavity 60 and a recoil spring 62 are found in the case of hydraulically actuated clutches K0, K1, and K2 in the case of an electro-mechanical actuation. FIG. 9 shows an electro-hydraulic actuation, wherein the electric motors 64 are connected to the actuating elements 68 with the aid of actuating bearings 66 for the purpose of actuation. Grooved ball bearings 70, needle bearings 72, and axial bearings 74 are also represented.

FIG. 10 also shows an embodiment of a portion of a dual clutch transmission arrangement corresponding to FIG. 4. The elements described above with respect to FIG. 9, such as actuating motors 64 or actuating bearings 66 are also present and, therefore, are not explained in greater detail.

In contrast to FIG. 9, FIG. 10 shows the possibility of providing a rotational-speed adaptive damper 76 in the wet space. A rotational speed-adaptive damper can be added to each embodiment in order to reduce vibrations. It is usually arranged on an input element of a clutch.

FIG. 11 shows a total view of the dual clutch transmission arrangement, wherein the clutch K2 is represented in addition to the clutches K1 and K0. In order to avoid repetitions with respect to the configuration of the left half, reference is made to the description of the figures with respect to FIGS. 9 and 10, in which these have already been described. The input 26 in the clutch K2 is connected to the connecting shaft 24; in this case, the input 26 of the clutch K2 is formed by the inner disk carrier 78. The outer disk carrier 80 forms the output of the clutch K2. The output 28 is connected to the transmission input shaft 30. The clutch K2 is arranged between the gear set planes of the transmission input shafts 22 and 30; this configuration corresponds to the configuration according to FIG. 3 in this regard.

Modifications and variations can be made to the embodiments illustrated or described herein without departing from the scope and spirit of the invention as set forth in the appended claims.

REFERENCE NUMBERS

-   1 motor vehicle -   2 first drive unit -   3 second drive unit -   4 dual clutch transmission arrangement -   5 differential -   6 transmission housing -   7 clutch bell housing -   8 gear set housing -   9 intermediate wall -   10 line -   12 line -   14 input -   16 output -   18 input -   20 output -   22 transmission input shaft -   24 connecting shaft -   26 input -   28 output -   30 transmission input shaft -   32 fixed gear -   34 idler gear -   36 shift element -   38 gear set plane -   40 gear set plane -   42 gear set -   44 countershaft -   46 fixed gear -   48 dual clutch arrangement -   50 inner disk carrier -   52 outer disk carrier -   54 outer disk carrier -   56 inner disk carrier -   58 dual-mass flywheel -   60 pressure compensating cavity -   62 recoil spring -   64 actuating motor -   66 actuating bearing -   68 actuating element -   70 grooved ball bearing -   72 needle bearing -   74 axial bearing -   76 rotational speed-adaptive damper -   78 inner disk carrier -   80 outer disk carrier -   K0 separating clutch -   K1 master clutch -   K2 master clutch 

The invention claimed is:
 1. A dual clutch arrangement (48) for a dual clutch transmission, comprising: a first clutch (K0); and a second clutch (K1), wherein an output (16) of the first clutch (K0) is connected to an input (18) of the second clutch (K1), wherein the input (18) of the second clutch (K1) is directly connectable to a second drive unit (3) such that the second drive unit (3) is operable to rotate the input (18) of the second clutch (K1) both when the second clutch (K1) is engaged and when the second clutch (K1) is disengaged.
 2. The dual clutch arrangement of claim 1, wherein the dual clutch arrangement (48) is a preassembled module.
 3. The dual clutch arrangement of claim 1, wherein the first clutch (K0) is a separating clutch for disconnecting an internal combustion engine (2) from the rest of a drive train.
 4. The dual clutch arrangement of claim 1, wherein the second clutch (K1) is configurated to connect to a transmission input shaft (22, 24).
 5. The dual clutch arrangement of claim 1, wherein the second clutch (K1) is configurated to connect to two transmission input shafts (22, 24).
 6. The dual clutch arrangement of claim 1, wherein the first clutch (K0) and the second clutch (K1) are radially nested.
 7. The dual clutch arrangement of claim 1, wherein an input of the first clutch (K0) is connectable to a first drive unit (2).
 8. The dual clutch arrangement of claim 1, wherein the input (18) of the second clutch (K1) is connected to the second drive unit (3) at a gearwheel 48 connected to the input (18) of the second clutch (K1).
 9. The dual clutch arrangement of claim 8, wherein the gearwheel 48 is arranged between the first and second clutches K0, K1.
 10. The dual clutch arrangement of claim 1, wherein the first and second clutches (K0, K1) are multi-disk clutches.
 11. The dual clutch arrangement of claim 1, wherein an output disk carrier of the first clutch (K0) and an input disk carrier of the second clutch (K1) comprise a common section.
 12. A dual clutch transmission arrangement, comprising the dual clutch arrangement of claim
 1. 13. A motor vehicle comprising the dual clutch transmission arrangement of claim
 12. 